Generally, the hair dryer is used to dry up the hair by heated air flow generated by heat wire such as Ni--Cr alloy wire. FIG. 1 shows the conventional hair dryer, comprising of body(8) which has hand grip(2) extending downward, an intake opening(4) and an exhaust opening(6) on the opposite side of it, a fan(11) driven by motor(10), a heat wire(9) disposed in front of fan(11) and a switch button(12) on the hand grip(2).
The user will press the switch button(12) to operate the motor(10) and the heat wire(9) to exhaust the heated air through the exhaust opening(6). But, because this type hair dryer may dry up the hair only by heat convection, the surface of hair may be easily heated, but the inner part of hair would not be sufficiently heated in a short time. And, if we heat the hair for long time enough to dry up into the inner part of hair, the hairline may be damaged by long time exposure of heated air. In addition, as the energy efficiency of heat wire is relatively low, the energy consumption is considerably high.